1. Field of the Invention
The present invention generally relates to a plug and socket connector comprising a socket connected to a power supply line and a corresponding plug which supplies electricity utilization equipment, the connector conforming to safety standards which specify that socket contacts must be disconnected from a voltage source when a plug is withdrawn from the socket.
More specifically, the present invention is particularly applicable to the construction of plug and socket connectors designed for safe use in inflammable or explosive mediums.
2. Discussion of Prior Art
In order to ensure that socket contacts remain dead when a plug and socket are separated, one normal practice in conventional devices uses a switch associated with a plug socket and disposed between the power supply line and the socket. For closing the circuit, at least, the switch is actuated by rotating the socket after insertion of plug. The disadvantage of this equipment lies in the fact that it requires a flexible connection between each contact of the socket and a corresponding input terminal. Thus, there exists the potential danger of damaging the end of each flexible connection as a result of successive operation of the device. Further, while it is possible in such a case to provide a quick break by making use, e.g., of resilient means released by an independent mechanism, the switch-closing operation remains conventional and is therefore not entirely satisfactory for use in an inflammable or explosive environment.
These drawbacks can be overcome by resorting to the use of a plug and socket connector in which provision is made for resilient pressure contact.